I bought it on sale for just 7.97, more I would not pay.
The download on Origin runs flawlessly - quite contrary to the previous review must not be uninstalled also the base game from CD.
Once you have completed the Dowload can install the extension. Then starts normally the Launcher and pointing down at the installed games, the new extension with on.
Here are actually relatively little new content available, for this reason I would not pay more.